Addition Of The Pre-Transfer Exposure Led; Measures Against Overheating Of The Developing Unit; Addition Of The Developing Fan - Canon iR105 Service Manual

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CHAPTER 2 NEW FUNCTIONS

5.3 Addition of the Pre-Transfer Exposure LED

The machine uses a process speed of 500 mm/sec (as opposed to 300 mm/sec in the

GP605 (iR600)) to support a copying speed of 105 pages/min (A4, Direct). To make up for

the decrease in charging on the photosensitive drum caused by the increase in the process

speed, the machine uses a photosensitive drum with a high degree of charging capacity and

a pre-exposure lamp with a short wave length (660 nm), thus ensuring a specific degree of

The higher process speed also decreases static charges used for separation; the pre-trans-

fer exposure LED is used to compensate for the decrease:

Pre-Transfer Exposure

Function: In an initial phase of the transfer process, the charges on the pho-

Timing: The LED is turned on 100 msec before the leading edge of an im-

The pre-transfer exposure LED is enabled/disabled according to paper type

in service mode (COPIER>OPTION>BODY>PAPER-TY):

PAPER-TY=1 (paper for 200V model) → ON

PAPER-TY=2 (paper for 208V/230V model) → OFF

The machine must consider possible overheating of the developing unit caused by the in-

creased process speed. When double-sided copying is performed continuously for a long

time, the heat used when fixing on the first sides can heat the developing unit, affect the

toner, and cause fogging. To prevent overheating, the following measures have been taken:

• addition of a developing fan

• modification of the developing cylinder cover

To prevent overheating of the developing assembly [1], a developing fan has been added

to the front of the machine. (See 8.2 Fans)

tosensitive drum (background potential) are reduced in advance,

thereby weakening the stack bonding between the photosensitive

drum and the transfer paper and ultimately encouraging separa-

age reaches a specific point until its trailing edge leaves it; (See

2000 2000 2000 2000

CANON iR105 REV.0 JULY 2001

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